pitest has a few tricks up its sleeve to keep overhead reasonable. For example (from http://pitest.org/faq/ http://pitest.org/faq/): > Per test case line cove

pitest has a few tricks up its sleeve to keep overhead reasonable. For example (from http://pitest.org/faq/ http://pitest.org/faq/): > Per test case line coverage information is first gathered and all tests that do not exercise the mutated line of code are disguarded. I've used pitest in real life and while it is quite a bit heavier than straightforward testing, it's definitely usable. I'm now using it on all Java projects, I wish there was something comparable for JavaScript!